The general objective of this proposal is to gather information about adjustment and the development of maladjustment in adolescents with mild mental retardation to facilitate severely needed theoretical advancement and clinical efforts. Specific aims are to: (a) evaluate change in adjustment, and the prevalence and incidence of maladjustment over 3 years in volunteer samples of 14 and 17 year olds with mild mental retardation; b) evaluate and compare the contribution to their variation in adjustment and development of maladjustment of different causal models consisting of disability, intrapersonal, social-ecological, psychosocial stress, and coping variables; and c) evaluate the utility of an integrative comprehensive disability-stress-coping conceptual model in explaining adjustment and development of maladjustment in this population. Variables to be investigated in this research were suggested by prior theory and research on adjustment in the mentally retarded as well as adaptation in the general population. The primary conceptual model being investigated integrates this knowledge with research conducted by the principal investigator on other handicapped populations. A prospective longitudinal multivariate design will be used in studying two age groups (14 and 17) each represented by two birth cohorts. Up to 280 mildly mentally retarded adolescents will be followed over three yearly assessments of observed variables related to the above noted conceptual variables. Adjustment will be measured over several domains (behavioral adjustment, social adjustment, and psychiatric symptoms) as reported by numerous informants (self, parents, teacher, clinician). Maladjustment will be defined statistically for these domains. Measurement procedures have been selected to be optimally suitable for this population. They will be administered to the adolescents themselves, their parents, and school personnel; in addition, direct observations will be used to measure family interaction and home environment variables. Structural equation with latent variables analysis will primarily be used to address the specific objectives. This research will begin to meet the need for any information about the mental health of adolescents with mental retardation, provide information useful for prevention and intervention, and strengthen theory relevant to stress and coping generally particularly as it pertains to handicapped populations.